According to the U.S. Energy Information Administration (EIA), crude oil production from unconventional reservoirs, primarily the organic-rich shales, accounted for almost 50% of total U.S. crude oil production in 2017. The organic-rich shale typically has extremely low permeability (nano-darcy to micro-darcy) and large surface area from the kerogen where hydrocarbon absorbed to. Special extraction processes are required in order to collect hydrocarbon from those ultra-tight, organic-rich shale rock samples in the laboratory. Currently, the industry standard extraction method for organic-rich rock sample analysis is Soxhlet extraction where the rock sample is placed into an extraction thimble where it is then extracted using organic-solvent such as dichloromethane (DCM) carbon disulfide (CS2), and pentane via the reflux cycle. The extracts are dissolved in the solvent forming a solution which is collected at the end of the extraction process. The solution is then blown down using thermal or vaporization procedure to remove the solvent, and the remaining extract is used for analysis. There are two critical disadvantages of the Soxlet extraction process: 1) the organic solvent is very strong and extracts all organic matter (both mobile and immobile hydrocarbon) from the rock; however, for most applications, only the mobile hydrocarbon part is of interest; 2) the blown-down process causes significant loss of the light-end of the hydrocarbon extracts due to vaporization, leading to reservation of only the heavy hydrocarbon (typically C13 and above) of the extracts from the shale rock samples.
Examples of prior art methods and system are described in the following references, all of which are incorporated herein by specific reference in their entireties for all purposes:
U.S. Pat. No. 6,661,000 B2, filed Dec. 11, 2002, entitled “Method for Measuring Absorbed and Interstitial Fluids.”
U.S. No. 7,445,041 B2, filed Aug. 9, 2007, entitled “Method and System for Extraction of Hydrocarbons from Oil Shale.”
U.S. No. 2010/0089132 A1, filed Feb. 30, 2008, entitled “Method and Apparatus for Obtaining Heavy Oil Samples from a Reservoir Sample.”
U.S. No. 2011/0108466 A1, filed Nov. 8, 2010, entitled “Method of Separating Hydrocarbons from Oil Rocks using Ionic Liquids.”
U.S. Pat. No. 9,638,821 B2, filed Mar. 16, 2015, entitled “Mapping and Monitoring of Hydraulic Fractures using Vector Magnetometers.”
Crisp, Phillip T., et al., 1985, “Flash Thermal Desorption as an Alternative to Solvent Extraction for the Determination of C8-C35 Hydrocarbons in Oil Shales,” Analytical Chemistry 1986, 58, pages 258-261.
Baltussen, E., et al., 2002, “Sorptive sample preparation—a review,” Anal. Bioanal. Chem. Chemistry (2002), 373, pages 3-22.
Schaefer, R. G., 1985, “GC Analysis of Hydrocarbons in Sedimentary Rocks using a Commercial Thermodesorption Unit as Injection Device”, Journal of High Resolution Chromatography & Chromatography Communication, Volume 8, Issue 5, Pages 267-269.
Abram, M. A., et al., 2017, “A New Thermal Extraction Protocol to Evaluate Liquid Rich Unconventional Oil In Place and In-situ Fluid Chemistry”, Marine and Petroleum Geology, Volume 88, sPage 659-675.
Jiang, C., et al., 2016, “Hydrocarbon Evaporative Loss from Shale Core Samples as Revealed by Rock-Eval and Thermal Desorption—Gas Chromatography Analysis: Its Geochemical and Geological Implications”, Marine and Petroleum Geology, Volume 70, Pages 294-303.
Piotrowski, Paulina K., et al., 2018, “Applications of thermal desorption coupled to comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry for hydrocarbon fingerprinting of hydraulically fractured shale rocks,” Journal of Chromatography A, 1579, pages 99-105.
Piotrowski, Paulina K., et al., 2018, “Elucidating Environmental Fingerprinting Mechanisms of Unconventional Gas Development through Hydrocarbon Analysis,” Analytical Chemistry 2018, 90, pages 5466-5473.
Piotrowski, Paulina K., et al., 2017, “Non-Targeted chemical characterization of a Marcellus shale gas well through GC×GC with scripting algorithms and high-resolution time-offlight mass spectrometry,” Fuel 215 (2018), pages 363-369.